The present invention relates to an actuator in a hard disk drive, and more particularly, to an improved actuator fixing apparatus for reducing the rotational inertia and the moving mass of an actuator body so that data access times are reduced.
A hard disk drive used as a memory device in a computer typically utilizes a rotatable actuator having a magnetic head on one end for reading and writing data from and to a surface of a magnetic disk. When the hard disk drive operates, rotation of the actuator must be carefully controlled in order to properly perform the read or write process. Rotation of the actuator is typically achieved through a voice coil motor that applies a torque upon a body of the actuator. In rotating the actuator, it is intuitive from classical physics that a greater moving mass produces a greater amount of rotational inertia. Accordingly, when designing actuator assemblies, it is desirable to minimize the moving mass of the actuator in order to retain greater control over the movement of the actuator.
One prior art reference directed towards this issue is U.S. Pat. No. 5,315,465 entitled Compliant Pivot Mechanism For A Rotary Actuator issued to Blanks. Blanks '465 discloses a pivot bearing structure for use in a rotary actuator that seeks to reduce the moving mass of the rotary actuator. In particular, tolerance rings are used to fix bearings to the actuator body to allow a thinner wall on the bore in the actuator body. Accordingly, the size of the completed assembly is reduced and the inertia of the actuator is lower. While this design possesses merit in its own right, we believe that an improved design can be contemplated.